I can't find any super solid data on bad attitude claims. It doesn't mean they aren't true, but I don't think they would be grounds to completely rule Sprong out of the possibility of a trade. He strikes me as a Vanek-esque player -- I've heard he's defensively irresponsible, but he can put the puck in the net. Either way, maybe a second trade in three years would help him change his attitude if it is indeed an issue.

I think Buffalo would certainly be losing in a one for one Risto for Henrique deal, but maybe with significant adds from Anaheim's side it would be possible. Henrique will be turning 30 next February, just came off a pretty bad season, and has a pretty rough (5,825,000 AAV) cap hit. Obviously Rakell is the big fish from Anaheim, but another interesting player would be Daniel Sprong. He's a pure goal scorer with a lethal shot, though Anaheim might not be willing to part with him, as they are rebuilding and he may be considered part of their young core.

Are you crazy!? Risto’s advanced stats are even worse than Laine’s! Our RD slot is filled, whereas our 2nd best RW is Conor freaking Sheary. If JB has the chance to trade Ristolainen (who may or may not be able to read) for a young, top five goalscorer in the league and doesn’t do he needs to be fired ASAP. I don’t give a rat’s ass about work ethic or ES goals if the guy can score 44 in one season. You bring up a legitimate concern with his contract, but that’s a good problem to have. I’d rather have that problem than seeing the Sabres finish near last in goals for next season, because I don’t see Tage Thompson and Kyle Okposo really being able to bring us out of the gutter.

https://frozenpool.dobbersports.com/frozenpool_nhle.php
This website uses a tool called NHLe, which attempts to predict NHL point totals based on those from other leagues. The site predicted Casey to score 32 points -- he currently sits at 25. While 25 < 32, I don't think there's anything to worry about concerning Casey's NHL development. NHLe doesn't account for many things, including the toll an 82 game season has on a 20 year old kid, and the fact that that kid might play for one of the worst teams in the league. An interesting tool nonetheless.